Rotary cutter for hydraulic dredges.



No. 768,106. PATENTED AUG. 23, 1904.

E. T. WILLIAMS. ROTARY CUTTER FOR HYDRAULIC DREDGES.

APPLICATION FILED DEC. 28, 1903. N0 MODEL' 8 SHEETS-SHEET 1.

No. 768,106. PATENTED AUG. 23, 1904* HT. WILLIAMS. ROTARY CUTTER POR-HYDRAULIG DREDGBS.

APPLICATION FILED DEC. 28, 1903.-

N0 MODEL. 3 SHEETS-SHEET 2.

PATEN'IED AUG. 28, I904.

E. T. WILLIAMS. ROTARY CUTTER FOR HYDRAULIC DREDGES.

APPLICATION FILED DEG. 28, 1903. 4

3 SHEETS-SHEET 3.

N0 MODEL.

UNITED, STATES Patented August 23, 1904.

PATENT OFFICE.

FROT 'AFIY CUTTER FOR HYDRAULIC DREDGES.

SPECIFICATION forming part of Letters Patent No. 768,106, dated August23, 1904'.

Application filed December 28, 1903. Serial No. 186,795- (No model.)

TO'a/ZZ whom it may concern.-

' Be it known that I, EZRA T. WILLIAMS, a citizen'of the United States,residing at Duluth, in the county of St. Louis and State of Minnesota,have invented certain new and useful Inn-- provements in Rotary Guttersfor Hydraulic Dredges, of which the following is a specification. 1

' My invention relates to rotary cutters employed in hydraulic dredgingapparatus, and has for its object to provide an improved cutter of'theclass referred to of increased efliciency as compared with cutters nowin use, which lncreased efliciency I secure principally by means of apeculiarformation and dispo-v sition of the blades, whereby the cutteris rendered self-cleaning and automatically drawsitself into the work.

is illustrated in the accompanying drawings, wherein Figure 1 is a sideelevational view of my improved cutter. Fig. 2 is a front end viewthereof. Fig. 3 is an inner face view of one of the blades detached.Fig. 4 is an edge viewof the blade shown in Fig. 3 lookingin thedirection indicated by the arrow. Fig. 5 is a transverse sectional viewon the line 5 5 of Fig. 3 looking in the direction indicated by thearrow. and Fig. 6 is an end view of a modified form of a blade-carryingspider.

Referring to the drawings, 10 designates the axial driving-shaft, theouter end thereof being preferably squared, as shown at 10 in Fig. 2, toreceive the hub of the cutter-head.

In the preferred form shown in Figs. 1 and 2 the spider of the headcomprises an axiallybored hub 11, fitted tothe squared end of the shaft10 and provided with two series of; radial arms 12 and 13, respectively.The companion arms of each pair of the series are not disposed parallel,but the arms of the rear series 13 are slightly back-set. angularlyv tothe arms of the forward series 12, and the arms of each pair are rigidlyconnected at their outer ends by abevel-edged connectionrplate- 14,these last-described parts being in practice preferably formed of anintegral casting.

loldesignates as an entirety each of. a series of blades secured to theseveral plates 14.

These blades have the peculiar formation substantially as illustrated inFigs. 1 to 5,inclu- .to the longitudinal axis of the head and shaft andhas its forward or advance end portion 16 bent quite sharply in thedirection of rotation 'ofthe head, the blade being also by virtue ofsuch bending warped 0r curled throughout its curved portionandterminating in apoint 17-, which lies substantially directly in ad-Vance of the rear edge of the immediately-v preceding blade, as moreclearly shown in Fig. 2. The forward or cutting edge ofeach blade(designated by 18) is inwardly bent, but

lies throughout in a plane intersecting the longitudinal axis of thehead and shaft and is formed of the requisite degree of sharpness,

while the rear or inner discharging edge 19 of theblade is curved bothinwardly and forwardly in the direction of rotation to the point 17.and' may be made of greater thickness and rounded or blunt, as shown inFigs. 3, 4, and 5. The inner or rear portion of the rear edge of theblade lying behind its supporting-spider is preferably tapered off, asshown at 19, in a direction substantially paralleLwith the shaft 10. Theinner face of each blade, as shown in the figures last referred to, isprovided with a longitudinally-extending dovetailed groove 20, open atits rear end 20, whereby the blade may be slipped over and interlockedwith the plate 14:, being secured to the latter by a series of screws orbolts 21, as shown in Fig. 1.

The above-described construction of. cutterhead leaves the forward orpenetrating face of the cutter open, the-curved and pointed end portionsof the several blades being well separated from each other and theskeleton form of the spider permitting the free and easy discharge ofthe excavated material inwardly of the cutter-head. The twist or curl.movement: of the head, which is excellently adapted to theself-cleaning of the head, the ICC angle of contact of the blades withthe spoil changing so rapidly that the spoil is dislodged automaticallyfrom the blades and does not stick thereto and clog the head, to whichlat ter result the unobstructed open spaces left between adjacent bladeslongitudinally of the cutter contribute also to a considerable degree.Furthermore, the described formation and relative psiti0ning of theblades produces a screw-like action as the cutter-headis rotated,whereby it automatically penetrates the material to be excavated andeliminates the necessity for any thrust thereupon to maintain it ineffective engagement with the material removed thereby. This screw-likeaction is facilitated by the fact that the penetrating points of theseveral blades are entirely free and unconnected, the spider beinglocated so far rearwardly thereof as to offer practically no obstructionto the penetrating action.

- knives, spider, and hub, are preferably made of steel, and thedouble-arm construction of the spider and hub affords great strength andrigidity and prevents the natural tendency of the blades to twist on thespider. The dovetailed detachable connection between said lastnamedparts, while consistent with the requirements as to rigidity, enablesindividual blades when broken or worn to be removed and substituted bynew ones without discarding the entire head.

While the described double-arm construc tion of spider is preferred forthe reasons above stated, yet it may within the purview of the inventionbe replaced by a construction employing a series of single arms to whichthe blades are attached. Such a construction is illustrated in Fig. 6,wherein 11 designates the hub and 12 a series of single radial armsextending therefrom, terminating in the connection-plates 14. Whenemploying the single-arm spider last described, 1 preferably add theretoan annular brace 22, connecting the outer portions of the arms 12 justinwardly of the connection-pieces 14?, which annular brace may be castintegral with or secured to said arms, as desired. A construction suchas that shown and described in connection with Figs. 1 and 2, whereinthe requisite strength and rigidity is obtained in the spider-armsalone, is preferred, however, because leaving a maximum of space betweenthe several cutters and longitudinally of the cutter-head for the freedischarge of the spoil.

From the foregoing it will be seen that my invention provides a powerfuland efficient cutter for hydraulic dredges and similar purposescharacterized as to its mode of operation by an automatic screw-likeaction, whereby it forces its own way into and through thematerialoperated upon, and, further, by an automatic-loosening andfreely-discharging action upon the material resulting from the Theentire cutter-head, including the peculiar warp or twist given to theblades, the freedom of their penetrating-points, and the ample spaceallowed for the dischargerd spoil longitudinally of and through thehead.

It is evident that the details of the d eseribed construction might bemodi lied somewhat both in respect to the particular formation of theblades and their connection to the shaft without departing from thespirit or sacrificing any of the described advantages of the in\'ention, and hence I. do not limit the latter to such details, except tothe extent that they are made the subject of specific claims.

1 claii l. A rotary cutter of the character described comprising a hubadapted to be secured to the end of a rotary shaft, said hub having aseries of radial arms, and a corresponding series of blades secured tothe outer ends of said arms, said blades forwardly of said arms beingwarped and bent in the direction of rotation of the cutter,substantially as described.

2. A rotary cutter of the character described comprisinga hub adapted tobe secured to the end of a rotary shaft, said hub having a series ofradial arms, and a corresponding series of blades secured to the outerends of said arms, said blades lying at an angle to the longitudinalaxis of the cutter and having their penetrating end portionswarped andbent in the direction of rotation of the cutter, substantially asdescribed.

3. A rotary cutter of the character described comprising a hub adaptedto be secured to the end of a rotary shaft, said hub having a series ofradial arms, and a corresponding series of blades secured to the outerends of said arms, said blades lying at an angle to the longitudinalaxis of the cutter and having sharp-poi nted penetrating end portionswhich are warped and bent in the direction of rotation of the cutter,substantially as described.

4. A rotary cutter of the character described comprising a hub adaptedto be secured to the end of a rotary shaft, said'hub having a series ofradial arms, a corresponding series of connection-plates on the outerends of said arms, and a corresponding series of blades secured by theirinner faces to said connection-plates, substantially as described.

5. A rotary cutter of the character described comprising a hub adaptedto be secured to the end of a rotary shaft, said hub having a series ofradial arms, a corresponding series of beveledged connection-plates onthe outer ends of said arms, and a corresponding series of cutter-bladesprovided on their inner faces with dovetailed grooves engaging saidconnectionplates, substantially as described.

6. A rotary cutter of the characterdescribed comprising a hub adapted tobe secured to the end of a rotary shaft, said hub having two series ofradial arms disposed one in rear of the other on said hub, and a seriesof cutter-blades ICC secured to the outer ends of each pair of frontends of each pair of front and rear arms, re- 10 and rear arms,respectively, substantially as spectively, and disposed at an angle tothe described. longitudinal axis of the cutter, substantially 7. Arotary cutter of the character described as described.

comprising a hub adapted to be secured to the end of a rotary shaft,said hub having tWo series of radial arms disposed one in rear of andWitnesses:

angularly back-set relatively to the other, and -H. A. DANCER,

a series of cutter-blades secured to the outer CLARA E. SKULs.

EZRA T. WILLIAMS.

